U.S. patent application number 12/009174 was filed with the patent office on 2009-07-16 for laproscopic electronic surgical instruments.
Invention is credited to Mel Kurtulus.
Application Number | 20090182324 12/009174 |
Document ID | / |
Family ID | 40851320 |
Filed Date | 2009-07-16 |
United States Patent
Application |
20090182324 |
Kind Code |
A1 |
Kurtulus; Mel |
July 16, 2009 |
Laproscopic electronic surgical instruments
Abstract
Surgical instruments are arranged for cutting and cauterizing
tissue with a closed-loop wire. An extension/retraction mechanism
forces a closed wire loop to constrict upon tissue enclosed by the
loop as the loop is retracted and drawn to a smaller size.
Simultaneously, as electrical current is passed through the wire
loop and further into the tissue, the tissue is resected and
cauterized. The closed wire loop is electrically coupled to a
remote power source via conductor(s) which cooperate with the
extension/retraction mechanisms. The extension/retraction mechanism
permits the loop to be extended and retracted as it is adjusted
from a first limit position towards a second limit position and
respectively back again. Further, the entire instrument is devised
to function in cooperation with common laparoscopic port systems.
Accordingly, the retraction mechanism permits the closed wire loop
to be extended and retracted through a small hollow tube which may
be placed in an abdomenal port installed in a surgical process. In
the alternative, these devices may be arranged with slight
modification to be either bi-polar or monopolar systems.
Inventors: |
Kurtulus; Mel; (La Jolla,
CA) |
Correspondence
Address: |
INTEGRITY IP
P.O. BOX 757
LA JOLLA
CA
92038
US
|
Family ID: |
40851320 |
Appl. No.: |
12/009174 |
Filed: |
January 16, 2008 |
Current U.S.
Class: |
606/37 |
Current CPC
Class: |
A61B 18/14 20130101;
A61B 2018/00595 20130101; A61B 2018/126 20130101; A61B 18/1482
20130101; A61B 2018/00601 20130101; A61B 2018/141 20130101; A61B
2018/1407 20130101; C08L 2201/12 20130101; A61B 2017/00867
20130101 |
Class at
Publication: |
606/37 |
International
Class: |
A61B 18/12 20060101
A61B018/12 |
Claims
1) Surgical instruments for use in laparoscopic procedures
comprising: an elongated tubular member; an elongated shaft member
slidably disposed coaxially within said tubular member whereby
linear displacements between the two are enabled; a closed wire
loop affixed at one end of the shaft member; and a power supply
electrically coupled to said wire loop the whereby electrical
current is passed from a first portion of the loop to tissues
thereby cutting and/or cauterizing the tissue.
2) Surgical instruments of claim 1, said closed wire loop is
arranged with two electrically isolated electrodes of opposing
pole.
3) Surgical instruments of claim 2, said wire loop is further
comprised of at least two electrical conductor elements (wire) of
opposing pole separated by an insulating coupler element.
4) Surgical instruments of claim 3, said insulating coupler element
further characterized as an electrical insulator forming a bond at
an end of each electrical conductor element.
5) Surgical instruments of claim 3, said "closed wire loop affixed
at one end of the shaft member" being further characterized as a
coupling to which each [from which the two electrical conductors
extend and separate spatially] of the two electrical conductors is
affixed, the coupling permitting the conductors to extend from the
shaft tip while maintaining electrical isolation from each
other.
6) Surgical instruments of claim 5, said shaft further comprising
at least one electrical conductor connecting to the closed loop and
further passing from an exit orifice of said tubular member.
7) Surgical instruments of claim 5, said tubular member further
comprising a tip with a mechanism for encouraging separation of
wire loop portions as a shaft is slid from a retracted position to
an extended position.
8) Surgical instruments of claim 1, closed wire loop extends from
at least one aperture in said tubular member and is driven from a
retracted position to an extended position and visa-versa in
response to displacements between said shaft member and said
tubular member.
9) Surgical instruments of claim 8, said tubular member is formed
to include a mechanical stop which prevents the tip end of shaft
from extending past a prescribed limit position with respect to the
tubular member.
10) Surgical instruments of claim 1, said tubular member and shaft
member have tactile grip elements which facilitate ergonomic grasp
by a surgeon's hands whereby they may be manipulated to yield a
displacement therebetween the tubular member and the shaft member.
Description
BACKGROUND OF THE INVENTIONS
[0001] 1. Field
[0002] The following inventions disclosure is generally concerned
with surgical instruments arranged for performing laparoscopic
surgeries and specifically concerned with an electrical cutting
instrument having a large aperture closed-loop wire with shape
memory.
[0003] 2. Prior Art
[0004] A `hysterectomy` is a surgical process to remove
reproductive organs of a female--and particularly the uterus.
Common means of effecting hysterectomy may typically include an
open abdominal process. Open abdominal surgery permits a surgeon
ready access and clear view of the organs in question. However,
significant increased risk of injury and infection is assumed as it
is necessary to cut large incisions in the abdominal wall to
sufficiently reach, manipulate and remove organ(s).
[0005] One alternative exists where the vaginal canal is used to
reach the uterus, but removing the uterus through the vagina
requires also removing the cervix which is not always desirable. It
is generally preferred that as little tissue as possible be removed
and it is excepted that where possible it is best to not disturb
the cervix. Accordingly, the procedure has serious disadvantage in
some cases.
[0006] While a hysterectomy may be achieved via many different
procedures, laparoscopic hysterectomy is preferred for its safety,
brevity, and reduced recovery time, reduces blood loss, low risk of
complications, among others. Modern medical science permits removal
of a uterus through very tiny incisions in the abdomen. Among
various versions of laparoscopic hysterectomy procedures are those
in which an electrical cutting knife and cauterizing tool are used
to separate or resect tissue and organs from where they are
attached.
[0007] In general, an electrode tipped instrument severs the uterus
from the cervix at the isthmus. In some cases, the ovaries are also
cut away from where they are attached at the uterus. In other
cases, the ovaries are separated from their attachment to the body
and are removed along with the uterus. To separate tissue in this
way, a surgeon uses the tip of an electrical knife to apply
electrical current to the region of tissue where resection is
desired.
[0008] In most conventional instruments, the electrical knife is
arranged as a monopolar system having a single electrode at the
instrument tip. A patient's body or bulk tissue forms an
electrically conductive path to a second electrode of opposing pole
(sometimes referred to as a `ground` or `earth`). Current density
is very high at the knife edge, but very low at the grounding
electrode. Accordingly, cutting and cauterization only occurs at
the tip of the instrument with very little or negligible damage to
tissues near the other electrode which is spread over a
considerably large area.
[0009] While monopolar systems are considered safe, it remains
desirable to avoid unnecessarily passing electrical currents
through healthy tissue. Where it is possible, a second electrode
should be placed where it can receive the electrical current just
after it passes through and cuts tissue at the site where it is
applied. Bipolar systems are sometimes arranged with both
electrodes incorporated in the cutting instruments tip. In this
way, electrical current passes from the first electrode, briefly
through a small portion of tissue, and thereafter returns at the
electrode of opposite pole. The electrical current only interacts
with a very small volume of tissue, and specifically with the
portion of tissue intended to be manipulated (cut or cauterized).
Because of this, bipolar systems are sometimes preferred as more
efficient and safe. However it is not always easy to configure to
electrodes in a shape such that the action of current corresponds
to the nature (shape, size, et cetera) of the tissue to be
manipulated. That is, sometimes the spatial nature of the tissue
does not cooperate well with the electrode shapes which might be
available at a tool tip. Constraints on current density further
complicate possible tool configurations. To provide two electrodes
(for bipolar instruments) in a spatially advantageous arrangement
which cooperates with the shape and sizes of organs or tissues
being addressed is the essence of effective instrument design.
[0010] Modern surgical technologies permit operations including
removal of large organs through very small abdominal incisions in
processes known as `laparoscopic surgery`. In a laparoscopic
surgery, a plurality of small abdominal incisions are made and
prepared with special port systems to permit elongated instruments
not larger than about 10 mm to about 15 mm in cross-section to be
inserted into the abdominal cavity. Video cameras, cutting
instruments, grabbing tools, among others are inserted via these
abdominal ports and a surgeon manipulates them to operate upon
various organs and tissues. After organs are removed via a
laparoscopic surgery, a patient quickly and easily heals as there
is considerably less damage to the abdominal wall. Further,
operating times are often reduced thus improving efficiency.
[0011] Part of the laparoscopic supracervical hysterectomy includes
cutting the uterus away from the fallopian tubes and its blood
supply. After it is clear of these, it must be severed from its
remaining attachment at the cervix. In most common laparoscopic
processes, and an electrical knife is used to resect first on one
side, and then on the other to finally separate the uterus from the
cervix. As the cutting and manipulation of the organ is done via a
video camera view of the abdominal interior, the process of
severing the uterus from the body can take a considerable amount of
time. It is a difficult process and takes very good concentration
from a well trained and experienced surgeon to do well and safely.
Even where a highly skilled surgeon in best conditions applies this
process, the resection takes a considerable amount of time and the
cut may be less than perfectly `smooth` or `clean` as it is
generally made via a series of individual cuts.
[0012] As such, certain inventions are now being introduced to
improve a doctor's ability to cut a uterus from the cervix. In one
important system, sold commercially by "Medical Dynamics" known by
its trade name: "Lap Loop", is described in the Journal of
Minimally Invasive Gynecology, Vol. 12, No. 4, July/August 2005. An
open loop wire is guided around the fundus portion of the uterus by
a specially shaped `introducer`. After the `cable` is routed
properly, the loop is closed by fastening the cable ends to special
hardware provided for such. The instrument includes this hardware
to couple a length of cable with specially prepared ends that
cooperate with a socket of the instrument. Because of the nature of
the hardware, there is no electrical isolation between various
elements and as such the device is restricted to monopolar
arrangements. Application of current causes the uterus to be
sectioned clean in a single plane leaving a preferred, tidy cut.
Further, the resection step is quick and smooth. However, this
instrument involves considerable effort to first properly thread
the cable around the uterus, and still further to couple the cable
ends to the tool sockets in order to realize a closed-loop before
application of electrical current.
[0013] While systems and inventions of the art are designed to
achieve particular goals and objectives, some of those being no
less than remarkable, these inventions have limitations which
prevent their use in new ways now possible. Inventions of the art
are not used and cannot be used to realize the advantages and
objectives of the inventions taught herefollowing.
[0014] It should be understood that all of herein referenced
materials provide considerable definition with regard to elements
of these inventions. Therefore, those materials are incorporated
herein by reference whereby this specification can rely upon them
for enablement of the particular teachings of each.
SUMMARY OF THESE INVENTIONS
[0015] Comes now, Mel Kurtulus with inventions of laparoscopic
surgical instruments having closed-loop arrangements for improved
resection efficiency including devices and methods of use of same.
It is a primary function of this these devices and methods to
provide efficient means of resecting human organs via laparoscopic
facility and systems. A fundamental difference between the instant
invention and those of the art can be found when considering its
closed-loop nature, and in some preferred versions its bi-polar
arrangements.
[0016] Laparoscopic electronic surgical instruments are devised in
which a closed-loop wire portion having shape memory (spring wire)
and additional facility to cause the closed-loop take shape and
size which cooperates with a human uterus. As such, these
instruments provide a loop which is easily passed over the uterus
when the instrument is in an extended state. Once passed over the
uterine fundus and properly fitted and constricted about an isthmus
portion of the tissue between the uterus and cervix, an electrical
current may be applied to effect a most efficient resection with
accompanied cauterization. The closed-loop wire made thereafter be
fully retracted and the entire instrument removed from the abdomen
via common "trocars" or abdominal ports used in conjunction with
other laparoscopic instruments. Among two of the most preferred
versions include: a bipolar version and a monopolar version.
[0017] A bipolar version, a single closed-loop is formed of two
electrode portions joined together at an electrical isolator. Each
of the electrodes may be coupled to the opposing poles of an
electrical current source whereby current passing between them
tends to cut and cauterized tissue in close proximity.
Specifically, when the closed-loop is constricted down upon a
cylindrical body of tissue, electrodes arranged in this fashion
tend to optimally inject electrical current in a preferred spatial
sense into tissue to cause most efficient cutting action.
[0018] In a monopolar version, a single closed-loop is formed of
one electrode coupled to an electrical source. A cooperating
`collector` electrode may be established at another portion of the
patient's body. When the closed-loop in the monopolar configuration
is closed down upon and constricted about a cylindrical body of
tissue, the loop injects electrical current in a manner to bring
about efficient resection.
[0019] In both cases, the instrument is arranged such that further
constriction of the closed-loop is applied while current is passed
to still better couple the devices electrode(s) to tissue yet to be
cut/cauterized. Further, these instruments are specifically
arranged to cooperate with a standard laparoscopic supporting
apparatus. In particular, they are elongated and quite narrow in
cross section so that they might be used with abdominal ports which
permit access to the interior of a body cavity via small incisions
therein.
OBJECTIVES OF THESE INVENTIONS
[0020] It is a primary object of these inventions to provide new
laparoscopic surgical instruments
[0021] It is an object of these inventions to provide electrical
resection instruments for laparoscopic use.
[0022] It is a further object to provide electrical resection
instruments having configurations which cooperate with a human
uterus.
[0023] It is an object of these inventions to provide electronic
resection instruments having a closed-loop system which facilitates
coupling with respect to a human uterus.
[0024] A better understanding can be had with reference to detailed
description of preferred embodiments and with reference to appended
drawings. Embodiments presented are particular ways to realize
these inventions and are not inclusive of all ways possible.
Therefore, there may exist embodiments that do not deviate from the
spirit and scope of this disclosure as set forth by appended
claims, but do not appear here as specific examples. It will be
appreciated that a great plurality of alternative versions are
possible.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0025] These and other features, aspects, and advantages of the
present inventions will become better understood with regard to the
following description, appended claims and drawings where:
[0026] FIG. 1 is a cross sectional diagram of a closed-loop
laparoscopic instrument of these systems;
[0027] FIG. 2 is another cross sectional diagram (of a tip portion
of one version of these instruments) with expansion in one
dimension for additional clarity;
[0028] FIG. 3 illustrates a tip portion of one version where the
instrument is in a retracted position as opposed to the contrasting
extended position illustrated in FIG. 2;
[0029] FIG. 4 illustrates an important preferred bi-polar version
of these systems; and
[0030] FIG. 5 illustrates an important preferred monopolar version
of these systems.
PREFERRED EMBODIMENTS OF THESE INVENTIONS
[0031] In accordance with each of preferred embodiments of the
invention laparoscopic surgical instruments having closed-loop
arrangements are provided. It will be appreciated that each of the
embodiments described include an apparatus and that the apparatus
of one preferred embodiment may be different than the apparatus of
another embodiment. Accordingly, limitations read in one example
should not be carried forward and implicitly assumed to be part of
an alternative example.
[0032] A laparoscopic instrument for use in hysterectomy surgeries
is fashioned with an electrode or electrodes which cooperate with
the particular size, nature, and characteristics of human organs
and in particular the uterus, ovaries, and cervix. Further, these
instruments are particularly arranged with structures which
cooperate with the physical nature of common laparoscopic
dimensions; including common sized abdominal ports or abdominal
volume, et cetera. An electrode or electrodes formed of an
electrically conductive materials such as metal and more preferably
spring wire arranged in a closed-loop sufficient in size to be
passed over a large uterus includes the active portion of a
laparoscopic resection instrument for cutting and
cauterization.
[0033] The closed wire loop is further arranged to cooperate with a
shaft member and a tubular member such that the wire loop is
retractable and extendable in conjunction with linear displacements
between the shaft and tube. Because a wire loop retracted into a
narrow tube is very thin, the arrangement is ideal for use in
laparoscopic type systems where small abdominal ports provide
access to the inside of an abdominal cavity. In some most important
versions, a closed wire loop is formed of two electrically isolated
portions thus forming a bipolar system enabling unique current flow
patterns particularly advantageous for cutting tissues of a
specific shape. In particular, where a wire loop is constricted
about a cylindrical body, a cross-sectional cut may be effected
cleanly and with ease. Most importantly, a closed-loop spring wire
system in a bipolar arrangement provides an electric current flow
pattern having good spatial relationship with the tissue to be
resected.
[0034] Once a closed-loop wire as described is passed over a uterus
and placed near where the uterus meets the cervix, the loop is
pulled into the tubular member such that the loop portion remaining
outside of the tube is constricted further down upon the tissue
which it surrounds. Once the wire is pulled into the tube as far as
the tissue allows, a current may be applied in a manner to resect
the tissue in contact with the wire. As the tissue is cut, the loop
may be further retracted into the tube and further constricted down
upon the remaining uncut tissue.
[0035] The aspect ratio of these instruments is quite large and
usually greater than about 10:1. As such, the drawing figures
cannot easily be drawn to proper scale in both dimensions on sheets
of acceptable size. It should be appreciated that scale is not
meant to be accurately depicted in these drawing figures which are
useful for illustration purposes by not engineering. For clarity,
one dimension may be greatly expanded in relation to an orthogonal
dimension. While FIG. 1 is presented with only slight distortion in
this regard, in the interest of clarity the other figures are
expanded in the transverse dimension with respect to the
instruments longitudinal axis. With reference to FIG. 1, a surgical
instrument suitable for use in laparoscopic operations is depicted
in two views including a first extended view, and a second
retracted view. "Extended" and "retracted" are with reference to
the active portion of the instrument, a closed wire loop.
[0036] The primary elements of the device include: an elongated
tubular member 1, a cooperating shaft member 2 of similar size and
aspect ratio, and a closed wire loop system. The closed wire loop
system is coupled thereto and affixed at the tip end 3 of the shaft
member. The shaft member is arranged whereby it shares a
longitudinal axis with the tubular member and moves slidably
therewithin a portion of that tubular member.
[0037] The closed wire loop system may be comprised of a plurality
of discrete portions. In some most preferred versions, a closed
wire loop is comprised of two electrically isolated conductor
elements 4, a coupler element 5 which is electrically insulative
and mechanically binds the two conductor elements at a junction
small in size. An insulative outer coating 6 covers and
electrically isolates either conductor which may run through the
center of the outer coating. Metallic portions of the wire loop may
be in some versions formed of metallic spring wire having a
"memory" shape and size which cooperates in particular with select
human organs; for example a uterus. When the closed-loop is in an
extended state, the spring wire encourages the closed-loop to take
a prescribed shape in accordance with the spring design imparted
during its manufacture. Normal use of the instrument, includes
passing the closed-loop over and around a uterus. Accordingly, it
is of great advantage if the size and shape of the loop
approximates or slightly exceeds that of the outside diameter of a
large human uterus, thus facilitating passing the loop over the
organ. It is for this reason that an instrument in a fully extended
state includes a loop of shape and size brought about via the
spring action of the metallic conductor, to cooperate with the
objective of passing the loop over a uterus.
[0038] The coupling between the closed wire loop and the shaft tip
end permits the loop to be mechanically affixed thereto such that
linear motion of the shaft imparts a translation force on the
closed wire loop which tends to either retract or extend the loop
with respect to the tubular member. The shaft and wire loop move
together as one within the tubular member. Further, the coupling
between the closed wire loop and the shaft is arranged to permit
extension of electrical conductor(s) through the shaft body such
that electrical current may be coupled from a remote source to the
closed wire loop. This is clarified in further detail in FIG.
3.
[0039] The closed wire loop further may be related to the tubular
member in that the tubular member may include a shaped tip 7 which
imparts a slight expanding force which encourages the loop to open
as the loop is pushed from the tubular interior to the extended
state. Thus the loop slightly expands therefrom and retracts
thereinto under motivation of the shaft which moves slidably within
the tubular member.
[0040] In some preferred versions, a specially arranged end of the
tubular member provides electrical isolation between two conductors
as it provides spatial isolation therebetween. A pair of channels 8
or elongated holes are provided in a solid electrically insulating
material such as a plastic or ceramic and each of two discrete
exposed wire portions of the closed wire loop pass through these
channels whenever the closed-loop is brought into a fully retracted
position. It is best if the extent of these channels is slightly
longer than the length of the exposed conductor on either side to
assure that electrical isolation is provided when the closed wire
loop is fully retracted. Close-up and detailed FIGS. 2 and 3 showed
this more clearly.
[0041] An `extended state` of the instrument represented in the top
half portion of FIG. 1 where the closed-loop which is large and
open and extends outwardly with respect to the tubular member. A
`retracted state` of the instrument is represented in the bottom
half portion of FIG. 1. where the closed-loop has been pulled into
the tubular member. A linear translation 12 between the tubular
member and the shaft member causes the shaft tip to be pulled
further into a cavity within the tubular member and accordingly
causes the closed wire loop 13 to simultaneously be pulled
thereinto. When fully retracted, a portion 14 of the closed wire
loop remains in the channels and a portion 15 along with the
coupler element 16 remains slightly external but tightly positioned
at the tubular member tip/orifice(s). The shaft member extends from
the tubular member at an exit orifice 17.
[0042] The arrangement is more readily understood in view of the
drawing of FIG. 2 which shows an expanded view along with a
cross-sectional view of the tubular member end with two orifices.
The tubular member 21 (shown only at a distal end) has axially
therein shaft member tip 22 where closed wire loop is affixed at
shaft tip 23 whereby displacement forces on the shaft are
transmitted to the closed wire loop. In some best versions, the
tubular member is further characterized as having an internal
cavity 24 which may be shaped to provide a mechanical limit or
"stop" whereby the shaft is prevented from further displacement in
the direction of the tubular end. Channels (two) 25 formed into the
solid electrical insulator material of the tubular member provide
orifices 26 from which portions of the closed wire loop may pass.
In one example, a majority portion 27 of the closed wire loop may
be comprised of an electrical spring wire conductor with an
insulating outer coating. An exposed portion of the wire connector
28 (also spring wire) has no insulator covering and promotes the
possibility of having electrical current emit therefrom. A ceramic
or plastic insulator "bead", or coupler element 29 mechanically
connects the two wire portions while simultaneously maintaining
electrical isolation therebetween. The coupler element may provide
a mechanical bond via a mechanical interlocking system,
alternatively via adhesives, or other bond system which ensures a
strong mechanical connection and electrical isolation. In cross
sectional view, the tubular member end 210 includes two orifices
211 through which the closed-loop wire portions may be passed.
[0043] In a retracted state, the instrument is described and
illustrated in the diagram of FIG. 3. Tubular member 31 has shaft
number 32 therein axially in cooperation therewith such that the
shaft may be displaced in a sliding action along the axis shared by
each. Tubular member cavity 33 may contain therein a portion of
retracted closed wire loop; more particularly conductor with
insulated outer coating 34. The outer coating may be preferably
made of a plastic material which forms a low coefficient of
friction with respect to the material from which the tubular member
is constructed. In this way, the relationship between the closed
wire loop and the channels of the tubular member is improved as the
wire loop will more easily slide from a retracted to extended state
and reverse. Silicon material is one example which provides an
electrical insulation function while at the same time serves to
provide a sliding system. Official notice is taken here that many
materials will be suitable for a similar function. Bare (metallic)
wire loop portions 35 do not include an insulator coating. This
portion of the closed wire loop is operable to emit electrical
current therefrom such that electrical current passes into/through
tissue to be cut or cauterized. However, when the instrument is in
a retracted state as shown in the figure, the bare wire portion is
protected against electrical shorts as they are contained in the
channels 36 of the tubular member end.
[0044] Coupler element 37 provides a mechanical bond between the
two wire portions and electrical isolation therebetween. This
coupler element additionally provides a mechanical stop against
pulling the shaft element too far down the axis of the tubular
element. When the closed wire loop is fully retracted, the coupler
element comes to a rest at the tubular element tip and prevents
further displacement between the shaft element and the tubular
element. Finally, electrical conductors 38 shown in phantom pass
from the closed wire loop where they are in electrical contact
therewith, through the shaft system to exit at the instrument's
other end where they may extend further to be energized by a remote
power supply. Electricity from a power supply outside the abdomen
passes to a wire loop inside an abdomen via the shaft and tubular
member which operate in cooperation with a trocar to provide access
to the uterus.
[0045] FIG. 4 illustrates a most important version of these
laparoscopic instruments. The device presented in the figure is a
bipolar version of the device. An elongated tubular member 41
shares an axis with shaft member 42. Two electrical leads 43 extend
from the end of the instrument and receive electrical power from
power supply 44 which may be switched by a surgeon and is arranged
to provide either DC, AC, or combinations of DC and AC electrical
currents. An insulated electrical lead of first polarity 45 carries
electrical current to closed wire loop portion 47 (non-insulative)
where it leaves 48 the conductor to pass through tissue. After
passing through tissue where the tissue may be cut and/or
cauterized, the current is collected 49 at the complementary
portion of the wire loop--at the exposed conductor of opposite
polarity. Insulated electrical lead 46 is a return path for
electrical current which passes through the shaft back to the
supply. It is in this manner that a bipolar instrument is
preferably realized. A bi-polar instrument in accordance with these
teachings provides an excellent current density distribution quite
suitable for resecting tissue. This is especially the case where
the tissue being resected is generally cylindrical in nature such
as the portion of the uterus near where it joins the cervix. That
is, the cutting action of the instrument is particularly designed
to cooperate with the particular anatomy to which it is intended to
be applied. The length of both exposed portions of the conductors
is chosen in view of the average size of this portion of the human
organs. In some cases, this size may be adjusted to produce an
instrument more suitable for larger or smaller persons. In
preferred versions, these conductors are between about 10 mm and 50
mm.
[0046] While in some versions, a bipolar closed wire loop tool as
described is most efficient, it remains clear that other versions
of these instruments, i.e. those arranged in monopolar
configurations also provide excellent benefit. Monopolar versions
are accompanied by added simplicity as only one electrical lead is
necessarily provided to carry current through the shaft member to
the closed wire loop. Tubular member 51 supports therein shaft
member 52 which might include the coupling of which further
improves an airtight seal of nicely fitted ".omicron." rings 53.
Laparoscopic operations sometimes used gas to inflate the abdominal
cavity, as such it is sometimes desirable in laparoscopic
instruments to provide for mechanisms to reduce loss of gas from
the abdomen.
[0047] A single conductor 54 forms the closed wire loop and
includes a covered portion and an exposed (no insulation) portion
55 from which electrical current 56 may pass into surrounding
tissue. In a monopolar system, electrical current may be collected
at a receiving conductor 57 coupled to a large area of a patient's
skin surface. Current from the instrument passes through tissue and
returns 58 to the electrical source via the conductor. Since the
conductor is coupled over a large area, the current density is
greatly reduced for all portions of tissue in which current passes
except for the tissue nearest the wire emitter (closed wire loop).
Cutting and cauterizing therefore only occurs at the wire loop
where the current density is highest. Electrical leads 59 include a
first lead of first polarity and a second lead of opposing polarity
where only one of these is necessarily passed through the
instrument's shaft element whereafter it is coupled at the closed
wire loop. Similar to the closed wire loop of the bi-polar
instrument, when the loop is constricted upon tissue, the exposed
portion of the conductor is well suited with respect to size when
compared to the site where it is desired that resection occurs.
[0048] To improve handling of these devices by the surgeons who use
them, both shaft member and tubular member may be terminated on one
end by ergonomically shaped handles; i.e. a shaft handle 510 and
tube handle 511. Abdominal port element 512 which may be a standard
device well known and used with a great plurality of laparoscopic
devices couples these instruments to a patient's abdominal cavity
in a conventional way.
[0049] One will now fully appreciate how high performance surgical
instruments for laparoscopic hysterectomy may be realized as
closed-loop systems and the advantages thereof. Although the
present invention has been described in considerable detail with
clear and concise language and with reference to certain preferred
versions thereof including best modes anticipated by the inventors,
other versions are possible. Therefore, the spirit and scope of the
invention should not be limited by the description of the preferred
versions contained therein, but rather by the claims appended
hereto.
* * * * *